The NHS is currently one of the key sources of national information on body mass in Australia. The most recent national data based on self reported height and weight come from the 2004-05 NHS. However, there are other collections which collect direct measures of height and weight and from different populations such as children. The 2007 NHS will present data based on both self report and direct measures.

OTHER DATA SOURCES

Self reported information relating to the body mass of adults is also collected in state health surveillance programs which are undertaken in several jurisdictions. The surveys are conducted using Computer Assisted Telephone Interviewing (CATI) methodology, whereas the NHS uses personal interviews to collect information.

The table below shows data for 2004, when BMI data were collected in all jurisdictions. Note that responses may be influenced by the differing age profiles of the states and territories. For example, South Australia and Tasmania have slightly older populations.

(c) Data collected through the 2004 Filling the Gaps Survey by DoHA, to provide national coverage of health data.

National Health Survey 2004-05 and Australia's health, AIHW 2006

The 2004 NSW Schools Physical Activity and Nutrition Survey (SPANS) provided an insight into overweight or obesity in children aged 5-16 years in NSW. SPANS measured the height, weight and waist of all participating students. It was conducted by the NSW Department of Health.

Overall, 25% of boys and 23% of girls were classified as overweight or obese. For boys, the rate of overweight or obesity was related to age, reaching a peak in 11-12 year olds before declining again. For girls, the highest rate of overweight or obesity was in 9-10 year olds.

Measured height and weight were last collected nationally for all people aged 25 years or more in the Australian Diabetes, Obesity and Lifestyle Study (AusDiab) in 1999-2000. AusDiab was the first national Australian longitudinal population based study, spanning five years. Respondents underwent a detailed physical examination by health professionals, which included measuring height, weight and blood pressure.

Around 55% of people who completed the survey questionnaire also provided physical measurements, but this figure does not include people who refused to participate in the study, suggesting that the true response rate is much lower. Adjustments to the sample were made in the weighting process to account for the fact that young males were under-represented in the physical examination (IDI, 2001).

In the AusDiab survey, almost 60% of Australians aged 25 years and over were classified as either overweight or obese, 2.5 times more than in 1980, according to the Risk Factor Prevalence Study run by the National Heart Foundation (Cameron et al. 2003).